In recent years, an action has been found that sterilizes bacteria floating in the air using positive ions and negative ions that are generated in the air to thereby make the air clean. Ion generating apparatuses such as air cleaners that apply this technology are attracting significant attention as apparatuses that favorably answer the needs of the modern comfort and health-oriented era.
However, because ions are invisible, their existence cannot be verified by direct sight. On the other hand, it is natural for a user of an air cleaner or the like to want to know whether or not ions are being generated normally, and whether ions of a desired concentration are being generated.
Therefore, an ion generating element that can easily determine the amount of ions and a remote control for an electric home appliance with a built-in ion sensor and the like have been disclosed as ion sensors that measure an ion concentration in the atmosphere. More specifically, an ion generating element that is equipped with an ion sensor portion that determines the amount of positive ions and negative ions generated from an ion generation portion, and a display that displays a determined ion amount is known (for example, see Patent Literature 1). In addition, a remote control for an electric home appliance with a built-in ion sensor is known that includes an ion sensor that measures an ion concentration in the atmosphere and a display that displays the current state of the electric home appliance (for example, see Patent Literature 2).